What is Shield:

Gawain's shield is the center of his protective gear, and a perfect symbol of knightly ideals. It represents at once the idea of protection from earthly harm, and with the pentangle symbol, the profound Christianity (and thus heavenly protection) that was necessary to knights' culture. It is also a reflection of the profound Christianity of the poet, for he explicitly takes time out from the story to describe in detail the shield's symbol - five blended triangles symbolizing truth and known in England as the 'infinite knot.'